The present invention relates to exhaust processor assemblies that are useable to process a combustion fluid. More particularly, the present invention relates to an inlet nozzle for an exhaust processor assembly which enables the inflow of combustion product to be distributed substantially evenly across the face of a substrate material without a significant buildup of back pressure due to the distribution of the flow.
Conventional exhaust processors generally include an inlet housing which is in communication with an exhaust manifold of an internal combustion engine and a monolithic substrate disposed within the processor to process various pollutants contained in a combustion product produced by the engine. Because of functional considerations, the size of the substrate is generally somewhat larger than the size of the exhaust conduit conducting the combustion product away from the engine. Because of this, problems arise in distributing the flow of the inflowing combustion product across a substantial portion of the surface of the substrate. It will be understood that it is advantageous to distribute the flow of combustion product as evenly as possible across the inlet face of the substrate to utilize the full capacity of the substrate and increase its useful life.
One object of the present invention is to provide an inlet for an exhaust processor assembly which provides for a substantially uniform distribution of the flow of the combustion product over the face of the substrate.
Another object of the present invention is to provide an inlet for an exhaust processor assembly which provides for a substantially uniform flow of the combustion product over the face of the substrate without significantly increasing the back pressure of the combustion product within the inlet.
Yet another object of the present invention is to provide an inlet for an exhaust processor assembly which provides for uniform flow distribution across the face of the substrate without increasing significantly the back pressure within the inlet and which is also easy to produce and manufacture.
According to the present invention, an exhaust processor assembly for processing a flow of combustion product supplied by a source means is provided. The processor assembly has a housing including inlet means coupled to the source means for admitting combustion product traveling in a certain flow direction into the housing and outlet means for exhausting combustion product from the housing.
The assembly also includes substrate means positioned in the housing in downstream relation to the inlet means for treating the combustion product admitted into the housing through the inlet means. The inlet means has a longitudinal axis that extends between the source means and the substrate means to define a predetermined axial dimension along the longitudinal axis.
The inlet means includes first diverging nozzle means communicating with the source means for providing an increase in the cross-sectional area of the inlet means in a flow direction over a first predetermined axial distance. The inlet means also includes second diverging nozzle means communicating with the substrate means for providing an increase in the cross-sectional area of the inlet means in the flow direction over a second predetermined axial distance. In addition, the inlet means includes transition means interconnecting the first and second diverging nozzle means in fluid communication for providing a substantially uniform cross-sectional area of the inlet means in the flow direction over a third predetermined axial distance. The summation of the first, second, and third predetermined axial distances is substantially equivalent to the predetermined axial dimension of the inlet means.
Diverter means is provided that is positioned in the inlet means for interrupting the flow of combustion product traveling through the inlet means toward the substrate means. The inlet means and the diverter means cooperating to provide distribution means for uniformly distributing the flow of combustion product introduced into the housing across the inlet face of the substrate. Such uniform distribution provides a distributed exhaust flow designed to load the entire volume of the substrate means substantially evenly to enhance combustion product treatment efficiency of the substrate means.
One feature of the foregoing structure is that the inlet means includes first and second diverging nozzle means for providing an increase in the cross-sectional area of the inlet means in the flow direction over a specified predetermined axial distance, and transition means interposed between the first and second diverging nozzle means for providing a substantially uniform cross-sectional area in the flow direction over a specified predetermined axial distance. One advantage of this feature is that by interposing a transition means with a substantially uniform cross-sectional area between first and second diverging nozzle means having increasing cross-sectional areas, the flow distribution of the combustion product flowing toward the substrate is enhanced.
Another feature of the foregoing structure is that diverter means is positioned in the inlet means to enhance the uniform distribution of the flow of the combustion product across the inlet face of the substrate. One advantage of this feature is that a distributed exhaust flow designed to load the entire volume of the substrate substantially evenly to enhance combustion product treatment efficiency is provided.
In preferred embodiments of the present invention, the first and second diverging nozzle means define first and third flow-conducting chambers, and the transition means defines a second flow-conducting chamber which is interposed between the first and third flow-conducting chambers. In addition, the diverter means is positioned in a portion of the first flow conducting chamber, or the second flow-conducting chamber, or may extend into a portion of these two chambers.
Also in preferred embodiments of the present invention, the first diverging nozzle means and the transition means cooperate to define an interface plane therebetween, and the diverter means is positioned such that it is substantially centered about the interface plane.
Also in preferred embodiments of the present invention, the source means is an inlet pipe which includes an open mouth having a specified cross-sectional area, and the diverter means includes a flow-interrupting member having a flow-receiving face and support means coupled to the inlet pipe for suspending the flow-interrupting portion in the inlet means in spaced relation to the inlet pipe open face. The flow-receiving face of the flow-interrupting member has a surface area that is substantially less than the specified cross-sectional area of the open mouth of the inlet pipe.
One feature of the foregoing structure is that the surface area of the flow-receiving face of the flow-interrupting member is substantially less than the cross-sectional area of the open mouth of the inlet pipe. One advantage of this feature is that the flow of combustion product from the inlet pipe toward the flow-receiving face does not increase the back pressure significantly in the inlet pipe.
In other preferred embodiments of the present invention, the flow-interrupting member is an elongated strap and the support means includes first and second elongated frame members situated in substantially spaced-apart parallel relation to each other. The first elongated frame member interconnects the inlet pipe and one end of the elongated strap, while the second elongated frame member interconnects the inlet pipe and the other end of the elongated strap.
One feature of the foregoing structure is that the first and second elongated frame members are connected directly to the inlet pipe and cooperate to support the elongated strap. One advantage of this feature is that the inlet pipe serves as the sole support for the flow-interrupting member, and the flow-interrupting member can be formed integrally with the inlet pipe to provide for an integral unit which is easier to manufacture.
Also in preferred embodiments of the present invention, the first predetermined axial distance is about 33-45% of the predetermined axial dimension. Also, the second predetermined axial distance is about 33-45% of the predetermined axial dimension, and the third predetermined axial distance is about 10-33% of the predetermined axial dimension. One feature of the foregoing structure is that the first, second, and third flow-conducting chambers are formed according to specified, predetermined requirements. One advantage of this feature is that, by forming the first, second, and third flow-conducting chambers according to specified requirements, the chambers cooperate with the diverting means to distribute the flow of combustion products substantially evenly across the face of the substrate.
Thus, the present invention provides an inlet for an exhaust processor assembly in which a specified contour of the sidewalls of the inlet defines specific relationships between cross-sectional areas of chambers within the inlet which, in combination with the location of a diverting means, cooperate to produce a substantially even flow of combustion product across the face of the substrate. By providing a chamber having substantially constant cross-sectional area interposed between two chambers having increasing cross-sectional area, and by placing the diverting means substantially near the interface between the first increasing cross-sectional area chamber and the constant cross-sectional area chamber, the flow pattern within the inlet is able to distribute the flow of combustion product to provide an even flow across the face of the substrate without increasing significantly the back pressure within the inlet or the source means.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.